The present invention relates generally to seals, and more particularly to annular seals suitable for use in gas turbine engines.
Annular seals are used in many applications, such as in pistons of combustion engines, in piping fittings, and in gas turbine engines. Annular seals are often used in gas turbine engines between components, such as vanes and blade outer air seals, to keep operating gasses and cooling gasses separate.
W-seals are a type of seal capable of withstanding high pressures and are designed to expand and contract axially and circumferentially, allowing w-seals to seal cavities between components of gas turbine engines subjected to a variety of conditions. However, w-seals have been known to degrade due to exposure to high temperature, high pressures, and uneven contact surfaces. Heat shields (secondary seals and secondary heat shields) have been used as a solution to this problem by reducing high temperature, high pressure, and/or stepped surfaces, but are still prone to failure and have caused other adverse effects such as negatively impacting blade tip clearance, thereby reducing engine efficiency.